Video chat is also known as video conferencing. This was developed at the same time as the television. They consisted at first of two closed-circuit television systems that were connected through cable. NASA used this type of communication on the first manned space flights. Instead of cables, two frequencies were used, UHF and VHF, one for each direction. This sort of conferencing was used for broadcasting from distant locations, but now, going one step further, satellite links are established using special trucks.

Because it was very expensive, this technology couldn’t be used as part of common long-distance applications. Some tried to use normal telephony networks for transmitting slow-scan video, but didn’t succeed due to the lack of picture quality and efficient video compression technique.

The 1980s marked the development of digital telephony transmission networks, like ISDN. The expansion of such networks led to the appearance of the first dedicated system from companies that specialized on this particular area. This is how video chat started. It was still quite costly, but throughout the 1990s, they evolved from expensive proprietary equipments to rather standard technology available for the general public.

In the 1990s something revolutionary was developed. IP based cam chat was developed and along with it more efficient video compression. This allowed video chat using you personal computer. The technology used is basically the digital compression of audio and video streams in real time. Codec, short for coder/decoder, is the common name used for the hardware and software that perform the compression.

As it was shown, web cam chat involves compressed audio chat and video chat streams. But how to we input or output them? Video input is usually done with a video camera or webcam. The output of video streams involves hardware like a monitor, television or a projector. Microphones are used to input audio streams into a computer and speakers allow the output.

After all the inputs and outputs, the audio and video streams are compressed up to 500 times. The resulting stream is then subdivided into labeled packets, which are sent to the recipient. The codec must be the same so the recipient’s hardware decodes the received packets, see the images and hear the sounds. Mostly digital networks like ISDN and IP are used. That is the basic process involved in cam chat.

There are some things that present a problem with this type of communication. Some people believe that eye contact is very important in a conversation. Traditional telephone conversations do not allow any eye contact, but web cam chat is believed to be even worse because it seems that the interlocutor avoids eye contact. This is, of course, a wrong impression and the problem may be overcome with advancing technology.